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Discussion Starter #1
I haven't posted in a while, my 2005 LLY has 165 K on it I just redid the entire cooling system new hoses new thermostats new water pump mishimoto radiator. I need to update my sig with all of the other mods done. Long story short it has a GT3794 Built trans lift pump CAI And EFI by GDP. On flat ground cruising at 75 my ECT is between 203 and 208 When towing my dumb trailer and skid steer on any gradual grade I see 230゚ plus before the fan brings it back down. I have pulled a vacuum on the cooling system there is no air in it whatsoever. I did not have my CTS in before I did all of these things so I don't have any reliable data as to what temps were before the work.

Is this outside of normal parameters?

(Also ambient temps between 90-100)


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That is too high for my taste. When does the coolent fan roar to life? I did the kodiak fan upgrade on mine an she stays 185-190 all day no matter what’s behind it. Also, is that coolent stack clean? Just things I’d check.
 

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Did you ever upgrade the turbo mouth piece, they were a known problem on the LLY. That seems a little warm for me but I don't think as long as the fan comes on and cools it down that it's going to harm it, also make sure to use tow haul mode anytime you tow and keep the rpms up on the engine.
 

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Did you ever upgrade the turbo mouth piece, they were a known problem on the LLY. That seems a little warm for me but I don't think as long as the fan comes on and cools it down that it's going to harm it, also make sure to use tow haul mode anytime you tow and keep the rpms up on the engine.
Yes I have the lbz mp coolant stack is clean I'm going to try different tstats

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If the stack is clean and you see 230 spike before the fan locks up, Might be time for a new fan clutch.

What's your trans fluid temp doing during all of this?
Built trans could be adding heat load to the stack....and since it runs thru the Rad 1st, could affect ECTs also.
 

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Discussion Starter #6
If the stack is clean and you see 230 spike before the fan locks up, Might be time for a new fan clutch.

What's your trans fluid temp doing during all of this?
Built trans could be adding heat load to the stack....and since it runs thru the Rad 1st, could affect ECTs also.
Towing it never passes 210 I have an aftermarket trans cooler. Before the cooler it would go 220+.

Popped the hood the past few mornings no hard hose but this morning it was hard as a brick bat. Looks like its time for HGs

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Discussion Starter #8 (Edited)
Does anyone have a recommended one stop shop for all the parts needed?
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Oil & coolant OK? No cross contamination? I had a hard upper hose and it turned out to be a plugged overflow cap. Soaked it in dawn detergent and solved it. However I was not running hot.

Good luck.
 

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Discussion Starter #10
Oil & coolant OK? No cross contamination? I had a hard upper hose and it turned out to be a plugged overflow cap. Soaked it in dawn detergent and solved it. However I was not running hot.



Good luck.
When I replaced the ENTIRE cooling system I did the cap from GM I had a bad experience with a parts store cap.

I'm going to do the tstats and fan clutch next week will update then.

The past 2 days I've had a soft hose in the morning. I'm a little bamboozled.

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it could be a slow leak, the head gasket might just have a pin hole, and being pressurized over time. if the truck is your only vehicle, just baby it and release the pressure every morning. watch your temps. granted that solution is only putting a band aid on a gun shot wound, but it can buy you some time.
 

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Discussion Starter #12
it could be a slow leak, the head gasket might just have a pin hole, and being pressurized over time. if the truck is your only vehicle, just baby it and release the pressure every morning. watch your temps. granted that solution is only putting a band aid on a gun shot wound, but it can buy you some time.
This is an old thread I wound up scattering the crank. Parted it out.

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That is too high for my taste. When does the coolent fan roar to life? I did the kodiak fan upgrade on mine an she stays 185-190 all day no matter what’s behind it. Also, is that coolent stack clean? Just things I’d check.
Can you provide a link for the kodiak fan upgrade? I need this bad, my LLY runs hot when towing. I even have the Cooler Towing auxiliary radiator installed.
 

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Get the Hayden 2886 severe duty fan clutch. It’s for the c4500/c5500 Kodiaks. You’ll thank me. I’ve had mine for years.
 
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